Filter elements and filter devices can be used for example in motor vehicles to filter fluids. For example, a fresh air system can have an air filter device to filter fresh air which is to be supplied to a combustion process in the combustion chambers of an internal combustion engine of the vehicle. It is of critical importance for optimal operation of the internal combustion engine to know the quantity or mass of air supplied to the combustion chambers as precisely as possible. To this end, an air flow meter, that is, a sensor for measuring the air mass or air quantity, is arranged in the fresh air system, expediently downstream of the filter device. It can be advantageous with regard to a compact design to arrange this air flow meter as close as possible to the filter device or as close as possible to the filter element.
A conventional filter element, which can be used as an air filter element, usually has an annular filter body consisting of a web-like, folded filter material, the filter body enclosing an inner space in the circumferential direction. Owing to manufacturing methods, such a filter body has an inhomogeneity at the point at which end folds of the filter material bound each other and are fastened to each other in the circumferential direction. For example, the end folds can be adhesively bonded to each other and correspondingly air-impermeable. This produces a flow through the filter element which is overall inhomogeneous in the circumferential direction. It has been found that the relative rotary position of the filter element in a filter housing has an effect on the measured values of the air flow sensor if the latter is positioned comparatively close to the filter element. Consequently, the air flow sensor must be calibrated when the filter element is inserted. This calibration process usually exceeds the material values of the filter element in terms of cost.